Solid State Audio Projects

4-channel-400W-amplifier.jpg 4 channel, 400 W amplifier3140 viewsThis 4-channel 400 W amplifier uses Hypex UcD400HG modules together with the corresponding power supply.
The whole is mounted inside a Galaxy 330 x 230 x 80 case.
For building instructions, have a look at this project's wiki.
Two such amplifiers has been working for over 2 years in my lounge, driving Linn Komponent 110 loudspeakers which each have 4 speaker inputs.

Francois Corthay - Switzerland

Project Page: 4 channel 400 W amplifier using Hypex UcD400HG modules

DIY-SE-Class-A-Mosfet-Amp.jpgClass-A 2SK1058 Renesas Mosfet Single-Ended Amp in Heatsink Enclosure3430 viewsThis is a build of Mark Houston's DIY Class-A 2SK1058 MOSFET Amplifier which was built without circuit board in order to have the shortest connections as possible and to meet the tradition of valve amps. The heatsinks of the fanless enclosure are heating up to little more than 40° C

Stefan - Germany

Juan-ZCA.jpgZCA by Juan2304 viewsGood day

I would like to add some of my pictures about my ZCA build from your site and I must say that this amp sound very good.

Regards
Juan

Hiraga-MC-Phono-Preamplifier.jpgHiraga MC Phono Preamplifier3621 viewsFinding I liked Moving Coil cartridges I tried my hand at yet another MC preamp. This one is a Jean Hiraga design and uses matched low noise bipolar transistors pairs and a +/- 6V source. The transistors Hiraga specifies are no longer available. But better replacements are the Analog Devices SSM2220 chips at $11 each (you need two). Hiraga specifies very large storage caps so I juiced this compact build with 1F (1,000,000uF). Plus I added 220uF low ESR caps and 0.22uF snubbers for better mid-range performance. Since this image I mounted an external switch to select between 220, 100 and 45 ohms of loading. A 25 turn trim pot allows adjustment of "0" volts on the input and Russian PIO caps decouple the output.

Mark – Mongrel Dog Audio

LePacific-MC-PrePre.jpgLe Pacific MC pre preamp3329 viewsHere is one of three Le Pacific MC pre preamp builds. All the construction is on veroboard (strip board). These builds have been tested with a two different cartridges with an output of 0.35mV and all work extremely well. The J-FETs are 2SK170 BL which are matched. The output capacitors are Russian mililtary PIO. The case colour is Sungold the same used on Paris. All phono preamp builds are battery powered.

Mark - retro-thermionic

Oatley_Electronics_K303_JFET_RIAA_Preamp_Kit.jpgOatley K303 JFET RIAA Preamplifier Kit4065 viewsThis is the second of the Oatley Electronics K303 two stage JFET phono preamps. I have built. The first build was in a "tinny" instrument case. The preamp sounded so good that I decided to construct another but this time in a heavy cast aluminum enclosure.

The K303 RIAA preamp kit comes complete with all required parts and a selectable 120/240V power supply. The RIAA section is all passive. The PS incorporates both a voltage doubler and a capacitor multiplier. The two different JFETs have been carefully chosen for their low noise and gain characteristics.

I have chosen a flame red epoxy enamel paint and separated the preamplifier section from the PS. The preamp is dead quiet and so far is the best sounding phono preamp I have built. At AU$30 for the kit, it’s a steal.

retro-thermionic

Pass_Aleph_4_DIY_Amp_Project.jpgVariant of the Aleph 4, a true 100W Class-A amplifier5368 viewsBuilt on a budget of less than £200 (mostly E-Bay). It generates some 400W of heat so the heatsinking is massive as are the power supplies. It uses 24 x IRFP244 MOS-FETs which are closely matched into groups of 6. This is the most exhaustive part of the build. Other than that the design is incredibly simple. PCBs are available from www.kk-pcb.com, although my article at diyAudio.com details the process and patterns that I used for my own build.

In the guise that you see in the photo, this amplifier runs at an internal temperature of 45 degrees C on a warm British Summer day, which is well below the 70-80 degrees that Nelson himself allows for his commercial products. The sound quality is simply STUNNING. I’m running an Arcam CD36 / Pumpkin-Shuntky Pre-amp / Passive Attenuator / B&W DM633 with Chord Chorus Silver Interconnects. The bass slam is accurate and endless, the sound stage perfect and the midrange just sweet as a nut. This replaced my A700, itself a clone of a Mark Levinson design, and absolutely knocks the ML into the ground.

The full project build can be seen at http://www.diyaudio.com/forums/pass-labs/172276-aleph-4-strickly-diy-project-build.html

Andy Freestone

dual_channel_2sk1058_2sj162_Mosfet_Power_Amplifier.jpgDual Channel 2sk1058 2sj162 Mosfet Power Amp5195 viewsThis is a dual channel 2sk1058 / 2sj162 mosfet power amplifier, built to be used a main L+R amplifier for my system. I had the amplifier tested after construction to ensure it was within rated specs - each channel is 200W (8 ohm) / 320w (4 ohm) @ 0.003% THD. I have designed a remote turn-on circuit to integrate with my receiver. Each channel has its own power supply with soft start on the line side of toroidal transformers. Cooling is achieved by tunnel heatsink assembly and a PWM fan controller. At start-up fan speed is 30%. Small thermistors are attached to the inside of the heatsinks to monitor temperature. Inputs are electronically balanced.

Ashley Webber
Brisbane , Australia

B2BO_ICEPower_1000ASP_modules_Par-Metal_Case.jpgB&O ICEPower 1000ASP modules5053 viewsThis is a high power audio amplifier project that I recently completed. The amplifier used two B&O ICEPower 1000ASP modules. Each amplifier module is rated at 1000 Watts. The two amplifier modules are housed in a Par-Metal aluminum case. The amplifier sounds amazing with my Epos ELS303 speakers.

See the other photographs.

Ed
Detroit, MI
USA

B2BO_ICEPower_1000ASP_modules_.jpgICEPower 1000ASP modules in Par-Metal Enclosure4069 viewsThis is a high power audio amplifier project that I recently completed. The amplifier used two B&O ICEPower 1000ASP modules. Each amplifier module is rated at 1000 Watts. The two amplifier modules are housed in a Par-Metal aluminum case. The amplifier sounds amazing with my Epos ELS303 speakers.

See the other photographs.

Ed
Detroit, MI
USA

Par-Metal_Case_ICEPower_1000ASP_modules.jpgPar-Metal Case with B&O ICEPower 1000ASP modules3808 viewsThis is a high power audio amplifier project that I recently completed. The amplifier used two B&O ICEPower 1000ASP modules. Each amplifier module is rated at 1000 Watts. The two amplifier modules are housed in a Par-Metal aluminum case. The amplifier sounds amazing with my Epos ELS303 speakers.

See the other photographs.

Ed
Detroit, MI
USA

BoZSE_-_Bride_of_Zen.jpgBoZoaC - Bride of Zen on a Cap3655 viewsThis build and my capless BoZSE both sound superior to my earlier BoZ builds. But which is better is hard to pick. Here is the finished BoZoaC. Two selectable Inputs on the rear and output on the left side. Small banana sockets on the right allow checking of the internal batteries without lifting the lid. The preamp could be powered through these. BoZoaC appears to have kept the great bass weight and extension of BoZSE with even better mids. Highs are about the same. Frequency range: 6hz -> 200khz. 13Vpp maximum out into 22K with 24V PS. Current draw = 12.5mA.
Mongrel Dog Audio

Point_to_Point_Bride_of_Zen_Preamplifier.jpgBoZoaC - Bride of Zen on a Cap4407 viewsAfter building a number of Bride of Zen (BoZ) preamplifiers I realised the whole circuit could be built on larger parts of itself. Here the whole BoZ circuit is constructed on the large output capacitors. The output caps are 10uF 100V polypropylene types. These were taped together along with two 1000uF of low ESR storage caps. Parts have been reduced to minimum size to keep signal path short and super glued to the rest on the cct. Silver solder and wirewrap wire is used throughout construction. There are two switchable inputs and the preamp can be powered by internal batteries (3 X 9V lithium) or an external supply. A bitumen and Al lined, non-magnetic low resonance ABS plastic case was used. Mongrel Dog Audio

Nelson-Pass-B1-Buffer-Preamp.jpg3287 viewsThe Pass B1 Buffer Preamp complete in Hammond Aluminum case. The B1 is a very transparent and PS tolerant preamp/ driver. Because it is a source follower some signal is lost (about 15%). But it is an excellent attenuator and offers a high impedance input and low output and is dead quiet. This build shares the same components as the DIY JFET BoZ preamp but sounds quite different.

For more information about this build see the Russian Pass B1 FET Preamp/Buffer thread on the forum.

Nelson-Pass-B1-Buffer-Preamp-rear.jpgNelson Pass B1 Buffer Preamp - rear3684 viewsDIY Nelson Pass B1 Buffer from the rear shows two selectable inputs and a single output. Compared to the Nelson Pass BoZ the mid range and treble I feel are more transparent but bass weight is less. The sound is completely un-coloured. This inexpensive simple preamp has a frequency extension from 5Hz to 780kHz and is very PS tolerant.
Mark Houston

For more information about this build see the Russian Pass B1 FET Preamp/Buffer thread on the forum.

Nelson-Pass-Bride-of-Zen-BoZ-Preamp-Aluminium-Case.jpgNelson Pass Bride of Zen (BoZ) Preamp - Aluminum Case3797 viewsThe finished Nelson Pass Bride of Zen (BoZ) Preamplifier. Where I though the Nelson Pass B1 buffer had excellent bass, the BoZ came in and made bass reproduction even heavier. Not more extended just weightier. Mid range and treble are extended and detailed. The Hammond aluminum cases sure are smart. You need a very, very quiet PS for this preamp. Any hum just leaches right through.

There is more info and notes in the JFET BoZ (Bride of Zen by Nelson Pass) thread on the forum.

P37aFinishedS.jpgElliott Sound Discrete transistor preamp P37A5334 viewsI made this for a very loyal customer with nothing but a schematic and vero-board. Worked first time. Low current draw (~3mA @ +/- 16V). The sound is very clean and flat. This preamp will definitely please the purist solid state amp lovers.

See the project page for the schematic: Minimalist Discrete Hi-Fi Preamp - Project 37, Revision A

More information about this build is available from the Elliott Sound Products Discrete SS Minimalist Hi-Fi Preamp thread.

Mark Houston

DSCF0800-C.JPGDIY-GENE Mark Levinson Clone 60Watt Class A Amplifier5555 viewsFor those that are less willing to create their own cases. Here is a completed DIY-GENE Mark Levinson Clone 60Watt / Ch Dual Mono Amplifier. It is hernia inducing weighing in at nearly 50Kg. The kit comes with most of the amplifier electronics built and tested and with all the casing components. All you need to do is to build the PSUs and put it all together. This example has 2 x 65-0-65V at 10A each. It runs very HOT as you would expect a high output Class A amplifier to run. Great care must be taken to mount the 12 x Output Transistors correctly, a small mistake cost me over £60.00 in burnt components. Note the Capacitor connections and the extremely BEEFY PSU.

Built by Andy Freestone

DSCF0797-C.JPGDIY-GENE Mark Levinson Clone 60Watt Class A Amplifier5583 viewsFor those that are less willing to create their own cases. Here is a completed DIY-GENE Mark Levinson Clone 60Watt / Ch Dual Mono Amplifier. It is hernia inducing weighing in at nearly 50Kg. The kit comes with most of the amplifier electronics built and tested and with all the casing components. All you need to do is to build the PSUs and put it all together. This example has 2 x 65-0-65V at 10A each. It runs very HOT as you would expect a high output Class A amplifier to run. Great care must be taken to mount the 12 x Output Transistors correctly, a small mistake cost me over £60.00 in burnt components. Note the Capacitor connections and the extremely BEEFY PSU.